1st Avenue & I-80 Interchange

Coralville Diverging Diamond interchange rendering

Diverging Diamond Interchange
The Iowa Department of Transportation is reconstructing the interchange at I-80 exit 242 and 1st Avenue with a diverging diamond interchange (DDI). The Iowa DOT is the lead agency on this project.

Contact Us

  1. Iowa Department of Transportation
    Catherine Cutler
    Transportation Planner         
    Email

    Iowa DOT logo


    City of Coralville
    Scott Larson
    City Engineer  
    Email

    1512 7th St.
    P.O. Box 5127
    Coralville, IA  52241

    Ph: 319.248.1720
    Fx: 319.248.1894
    Staff Directory


Updates: Current & Upcoming Work
Major construction started in March 2023. 1st Avenue is reduced to one lane in each direction over I-80 into fall 2024. Drivers should anticipate traffic delays and plan accordingly.

1st Avenue
On 1st Avenue: Northbound & Southbound (Between 9th Street and Holiday Road): 
November 14, 2023-Fall 2024*:
  • Northbound and southbound traffic shifts to the east side of 1st Avenue across I-80 and is one lane in each direction (head-to-head).
December 4, 2023-mid April 2024:*
  • On the south side of the interchange, pavement markings will be adjusted to improve lane assignments for northbound and southbound 1st Avenue drivers. 
1st Avenue: Northbound (approaching E. 9th Street)
November 14-mid April 2024*:
  • Northbound 1st Avenue approaching E. 9th Street will have only one thru lane. The other thru lane becomes a dedicated right turn lane onto E. 9th Street.
  • Once northbound 1st Avenue drivers reach the new bridge over I-80, 1st Avenue will widen to provide a separate left turn lane onto the westbound I-80 on ramp and a through lane to continue north on 1st Avenue.
1st Avenue: Southbound (approaching I-80):
Starting November 14, 2023*:
  • Southbound traffic on 1st Avenue will now be able to turn left onto the eastbound I-80 on ramp.
December 4, 2023-mid April 2024:*
  • On the north side of the interchange, the dedicated southbound 1st Avenue right turn lane to the westbound I-80 on ramp will be moved adjacent to the southbound 1st Avenue through lane. Drivers will turn right at the traffic signal to head west on I-80.  

Interstate 80
I-80 Eastbound Off-Ramp: to 1st Avenue Northbound (Exit 242)
November 14-December 11, 2023:
  • Due to the elevation difference between old and new 1st Avenue on the south side of the interchange, eastbound I-80 off-ramp traffic approaching 1st Avenue will not be able to turn left onto northbound 1st Avenue. That movement will be detoured east on I-80 to Exit 244 (Dubuque St), and back west on I-80 to 1st Avenue. 
I-80 Eastbound Off-Ramp: to 1st Avenue Northbound or Southbound (Exit 242)
December 11, 2023-mid April 2024:
  • Exiting I-80 eastbound traffic will be shifted to the new exit ramp and will be able to turn left and right to go northbound or southbound on 1st Avenue. 
  • The I-80 on ramp will continue to be where it is today until construction is completed on the new on ramp.
I-80 Eastbound (Exit 242)*:
March 6-December 31, 2023: 
  • Intermittent lane closures overnight between 7:00 pm and 6:00 am Monday through Thursday, and between 9:00 pm and 6:00 am Sunday.
I-80 Westbound (Exit 242)*:
March 6-December 31, 2023*: 
  • Intermittent lane closures overnight between 7:00 pm and 6:00 am Monday through Thursday, and between 9:00 pm and 6:00 am Sunday.


Bicyclists & Pedestrians
Starting November 10, 2023*:
  • Bicyclists and pedestrians will use the new trail alignment along the east side of 1st Avenue.
  • The trail goes from the northeast corner of E. 9th Street, through two new trail tunnels, over the new trail bridge, along the east side of 1st Avenue to the River Products/Hotel intersection, and to the west side of 1st Avenue via a pedestrian crosswalk signal.
  • The existing trail along the west side of 1st Avenue between E. 9th Street and the Hotel entrance will be removed with the next phase of interchange reconstruction.


*(Dates subject to change based on weather and unforeseen circumstances)
**(There will be intermittent closures and detours throughout the construction season which will be communicated prior to the closures)

Comment: Davenport RCE (800-262-5145) 

Please check 511ia.org for the latest updates to the project.

I-80 Eastbound to 1st Ave Northbound (effective Nov. 14, 2023)

Phase3 Stage1 Detour Nov. 2023

Traffic Movements (effective Nov. 14, 2023)

Phase3 Stage1 Overview Nov. 2023

Drone Images
The drone images below were captured by IDOT.

October 17, 2023

1st Ave I-80 interchange construction Oct 17, 2023

October 17, 2023

1st Ave I-80 interchange construction Oct 17, 2023

October 17, 2023

1st Ave I-80 interchange construction Oct 17, 2023

May 30, 2023

DDI-drone-images-2023-05-30-1_Page-1-labels_1000x667

May 30, 2023

DDI-drone-images-2023-05-30-3_Page-3-labels_1000x667

Project at a Glance
The existing interchange at I-80 exit 242 is the original configuration constructed in the 1960s when I-80 was built through Iowa. The new diverging diamond interchange will provide safety improvements and is designed to handle projected traffic volumes.

Major construction began in mid-March 2023, and reduces 1st Avenue to one lane in each direction over I-80. 1st Avenue will remain one lane in each direction over I-80 into fall 2024.

The prime contractor is Peterson Contractors, Inc., of Reinbeck, Iowa. The Iowa DOT is administering and inspecting the project.

Highlights Once Complete

  • Diverging diamond interchange design eliminates the left turn phase at signalized intersections. This reduces overall traffic delay while also providing a significant safety improvement since left-turning traffic is no longer crossing opposing traffic lanes.
  • New grade-separated trail with underpasses and a trail bridge over I-80.
  • New 1st Avenue bridges accommodate the potential future widening of I-80.
  • New, signalized intersection to serve Iowa River Landing Place and the Magellan Terminal. 
  • New stormwater management practices, traffic signals, roadway lighting, and aesthetic treatments. 

  1. Traffic & Pedestrian Impact
  2. Timeline
  3. Cost

Traffic & Pedestrian Impact

  • The project will utilize staged construction, including temporary pavement and temporary traffic signals. 
  • One lane of traffic will be maintained in each direction on 1st Avenue at all times.  
  •  Drivers should anticipate traffic delays and plan accordingly. 
  • After the 1st Avenue Trail closures in October and November 2022, pedestrian access along 1st Avenue over I-80 should not be impacted again for the remainder of the project.

Learn More
Iowa Department of Transportation
Iowa DOT project website

Watch Video: Navigating the Diverging Diamond Interchange
 

Stay Informed


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